Method of forming multiple coating on dry plating member and molded article manufactured using the same

ABSTRACT

Disclosed are methods of forming a multiple coating on a dry plating member and a molded article manufactured using the same. The method may include applying a color coating agent onto a surface of a plating layer of a plating member and then drying the applied color coating agent to form a color coating layer, and applying a clear coating agent onto a surface of the color coating layer and curing the applied clear coating agent to form a clear layer, wherein the plating member includes a substrate, an undercoat layer formed on a surface of at least a part of the substrate, and a plating layer formed on a surface of the undercoat layer.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a divisional of U.S. patent application Ser.No. 16/903,665, filed Jun. 17, 2020, which claims, under 35 U.S.C. §119(a), the benefit of priority to Korean Patent Application No.10-2019-0084063 filed on Jul. 11, 2019. The entire disclosure contentsof these applications are herewith incorporated by reference into thepresent application.

BACKGROUND (a) Technical Field

The present disclosure relates to a method of forming a multiple coatingon a dry plating member and a molded article manufactured using thesame.

(b) Background

Plastic parts utilized in applications such as construction members andinterior and exterior parts for vehicles include a plating layer formedon the surface thereof in order to secure corrosion resistance and wearresistance and improve the appearance thereof. In addition, in recentyears, the importance of surface treatment technology for interior andexterior parts for vehicles has increased with the goal of extending thelife of vehicle parts or increasing the safety thereof by securingdurability from various aspects as well as improving the appearancethereof.

Meanwhile, a radiator grille, which is a vehicle component, is a devicethat acts as a vent that receives air required for cooling a radiator.The radiator grille is generally installed in the form of a lattice infront of the radiator to act as a vent, and it is also called a “frontmask” since it includes a front part such as a headlamp.

The above information disclosed in this Background section is providedonly for enhancement of understanding of the background of the presentdisclosure, and therefore it may include information that does not formthe prior art that is already known in this country to a person ofordinary skill in the art.

SUMMARY

The present disclosure has been made in an effort to solve theabove-described problems associated with existing solutions.

It is one object of the present disclosure to provide a method offorming a multiple coating on a dry plating member to provide chippingresistance, scratch resistance, and durability.

It is another object of the present disclosure to provide a method offorming a multiple coating on a dry plating member to provide improvedappearance, chemical resistance, and weather resistance.

It is another object of the present disclosure to provide a method offorming a multiple coating on a dry plating member that is lightweightand exhibits excellent light resistance and adhesion between coatinglayers.

It is yet another object of the present disclosure to provide a moldedarticle manufactured using the same.

The objects of the present disclosure are not limited to those describedabove. The objects of the present disclosure will be clearly understoodfrom the following description and are capable of being implemented bymeans defined in the claims and combinations thereof.

In one aspect, the present disclosure provides a method of forming amultiple coating on a dry plating member. In one embodiment, the methodmay include applying a color coating agent onto a surface of a platinglayer of a plating member and then drying the applied color coatingagent to form a color coating layer, and applying a clear coating agentonto a surface of the color coating layer and curing the applied clearcoating agent to form a clear layer, wherein the plating member includesa substrate, an undercoat layer formed on a surface of at least a partof the substrate, and a plating layer formed on a surface of theundercoat layer, wherein the color coating agent includes 10 to 35% byweight of a modified acrylic resin, 1 to 25% by weight of a pigment, and40 to 80% by weight of a first solvent, and wherein the clear coatingagent includes 10 to 30% by weight of a polyester-modified acrylicresin, 5 to 25% by weight of an acrylic oligomer, 5 to 45% by weight ofan acrylic monomer, 1 to 15% by weight of a photoinitiator, and 10 to75% by weight of a second solvent.

In one embodiment, the undercoat layer may be formed by applying anundercoating agent including 10 to 65% by weight of an acrylic compound,0.1 to 5% by weight of a polyester-modified acrylic resin, 0.5 to 5% byweight of a photoinitiator and 30 to 75% by weight of a third solvent onat least one surface of the substrate, followed by curing, and theacrylic compound may include an acrylic monomer and an acrylic oligomer.

In one embodiment, the plating layer may be formed by depositing a metalon a surface of the undercoat layer.

In one embodiment, the color coating layer may be formed by drying theapplied color coating agent at 60 to 80° C.

In one embodiment, the modified acrylic resin included in the colorcoating agent may have a weight average molecular weight of 5,000 to50,000 g/mol.

In one embodiment, the polyester-modified acrylic resin included in theclear coating layer may have a weight average molecular weight of 5,000to 50,000 g/mol, a hydroxyl value of 30 to 250 mgKOH/g and a glasstransition temperature of 40 to 90° C.

In another aspect, the present disclosure provides a molded articlemanufactured using the method of forming a multiple coating on a dryplating member. In one embodiment, the molded article may include asubstrate, an undercoat layer formed on a surface of at least a part ofthe substrate, a plating layer formed on a surface of the undercoatlayer, a color coating layer formed on a surface of the plating layer,and a clear layer formed on a surface of the color coating layer,wherein the color coating layer is formed using a color coating agentincluding 10 to 35% by weight of a modified acrylic resin, 1 to 25% byweight of a pigment and 40 to 80% by weight of a first solvent, andwherein the clear coating layer is formed using a clear coating agentcomprising 10 to 30% by weight of a polyester-modified acrylic resin, 5to 25% by weight of an acrylic oligomer, 5 to 45% by weight of anacrylic monomer, 1 to 15% by weight of a photoinitiator and 10 to 75% byweight of a second solvent. In one embodiment, the molded article mayfurther include at least one of 0.1 to 5% by weight of a lightstabilizer, 0.1 to 5% by weight of a heat stabilizer, 0.1 to 5% byweight of an adhesion promoter and 0.1 to 10% by weight of an additivebased on the total weight of the clear coating agent.

Other aspects and preferred embodiments of the present disclosure arediscussed infra.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other features of the present disclosure will now bedescribed in detail with reference to certain exemplary embodimentsthereof illustrated in the accompanying drawings which are given belowby way of illustration only, and thus are not limitative of the presentdisclosure, and wherein:

FIG. 1 shows a method of forming a multiple coating on a plating memberaccording to an embodiment of the present disclosure;

FIG. 2 shows a molded article according to one embodiment of the presentdisclosure; and

FIG. 3 is an image showing molded article specimens produced accordingto Examples 1 to 2 of the present disclosure.

DETAILED DESCRIPTION

In the following description of the present disclosure, detaileddescriptions of known functions and configurations incorporated hereinwill be omitted when the same may obscure the subject matter of thepresent disclosure.

The terms which will be described below are defined in consideration offunctions in the present disclosure and may be changed according tointentions or customs of users or operators, and thus the definitionsshould be understood based on the contents throughout the specificationfor describing the present disclosure.

Method of Forming Multiple Coating on Dry Plating Member

One aspect of the present disclosure relates to a method of forming amultiple coating on a dry plating member. FIG. 1 shows a method offorming a multiple coating on a dry plating member according to anembodiment of the present disclosure. Referring to FIG. 1, the method offorming the multiple coating on the dry plating member includes (S10)forming a color coating layer and (S20) forming a clear layer.

More specifically, the method of forming the multiple coating on the dryplating member may include (S10) applying a color coating agent onto asurface of a plating layer of a plating member and drying the appliedcolor coating agent to form a color coating layer, and (S20) applying aclear coating agent onto a surface of the color coating layer and curingthe applied clear coating agent to form a clear layer. The color coatingagent contains 10 to 35% by weight of a modified acrylic resin, 1 to 25%by weight of a pigment and 40 to 80% by weight of a first solvent, andthe clear coating agent contains 10 to 30% by weight of apolyester-modified acrylic resin, 5 to 25% by weight of an acrylicoligomer, 5% to 45% by weight of an acrylic monomer, 1 to 15% by weightof a photoinitiator, and 10% to 75% by weight of a second solvent.

Hereinafter, the method of forming the multiple coating on the dryplating member according to the present disclosure will be described indetail step by step.

(S10) Forming Color Coating Layer

In this step, a color coating agent is applied onto a surface of aplating layer of a plating member and then dried to form a color coatinglayer.

The plating member includes a substrate, an undercoat layer formed onthe surface of at least a part of the substrate, and a plating layerformed on the surface of the undercoat layer.

In one embodiment, the substrate may include polycarbonate (PC),polyvinyl chloride (PVC), polyolefin, polystyrene (PS), polyoxymethylene(POM), ethylene propylene diene monomer (EPDM), polymethyl(meth)acrylate (PMMA), acrylic-styrene-acrylonitrile (ASA),acrylonitrile-butadiene-styrene (ABS) and polyalkylene terephthalate orthe like. For example, the substrate may include acrylonitrile butadienestyrene (ABS).

The plating layer is formed in order to ensure the glossiness andcorrosion resistance of an injection-molded article according to thepresent disclosure. In one embodiment, the plating layer may be formedusing dry plating. In one embodiment, the plating layer may be formed bydepositing a metal on the surface of the undercoat layer. For example,the deposition may be a physical vapor deposition method (PVD), such asvacuum deposition, sputtering or ion plating. For example, the metal mayinclude at least one of stainless alloy (SUS), iron (Fe), aluminum (Al),titanium (Ti) and chromium (Cr).

In one embodiment, the thickness of the plating layer may be 1 to 50 μm.Within this thickness range, the plating layer can exhibit excellentadhesion and appearance.

In one embodiment, the undercoat layer may be formed by applying anundercoating agent containing 10 to 65% by weight of an acryliccompound, 0.1 to 5% by weight of a polyester-modified acrylic resin, 0.5to 5% by weight of a photoinitiator and 30 to 75% by weight of a thirdsolvent on at least one surface of the substrate, followed by curing. Inone embodiment, the undercoat layer may be formed by applying anundercoating agent, followed by photocuring.

Hereinafter, the ingredients of the undercoating agent will be describedin detail.

Undercoating Agent

(1) Acrylic compound: In one embodiment, the acrylic compound mayinclude an acrylic monomer and an acrylic oligomer.

In one embodiment, the acrylic monomer may include an acrylate monomerhaving two or more polymerizable functional groups.

The acrylic monomer may be present in an amount of 5 to 30% by weightbased on the total weight of the undercoating agent. When the acrylicmonomer is present in an amount within the range defined above,adhesion, photocuring efficiency and workability can be excellent.

In one embodiment, the acrylic monomer may include an acrylate oligomerhaving two or more polymerizable functional groups. The acrylic oligomermay have a weight average molecular weight of 500 to 6,000 g/mol. Themechanical properties of the undercoat layer can be excellent under theconditions defined above.

The acrylic oligomer may be present in an amount of 5 to 45% by weightbased on the total weight of the undercoating agent. When the acrylicoligomer is present in an amount within the range defined above,adhesion, photocuring efficiency and workability can be excellent.

In one embodiment, the acrylic compound may be present in an amount of10 to 65% by weight based on the total weight of the undercoating agent.When the acrylic compound is present in an amount within the rangedefined above, photocuring efficiency and durability of the undercoatlayer can be excellent.

For example, the acrylic monomer and the acrylic oligomer may be presentin a weight ratio of 1:0.5 to 1:3. Miscibility, photocuring efficiencyand workability can be excellent within the above weight ratio.

(2) Polyester-modified acrylic resin: the polyester-modified acrylicresin may be included in order to improve the elasticity, flexibilityand interlayer adhesion of the undercoat layer.

In one embodiment, the polyester-modified acrylic resin may be preparedby polymerizing an unsaturated polybasic acid with a first reactionproduct prepared through condensation between a polyhydric alcohol and apolybasic acid to prepare a polyester precursor having a double bond atthe end thereof and then polymerizing the polyester precursor with anacrylic monomer.

In one embodiment, the polyester-modified acrylic resin may have aweight average molecular weight of 5,000 to 50,000 g/mol, a hydroxylvalue of 30 to 250 mgKOH/g, and a glass transition temperature of 40 to90° C. Under the above conditions, the viscosity can be easily adjusted,and thus workability can be excellent, and hardness, adhesion andscratch resistance of the undercoat layer can be superior.

In one embodiment, the polyester-modified acrylic resin may be presentin an amount of 0.1 to 5% by weight based on the total weight of theundercoating agent. When the polyester-modified acrylic resin is presentin an amount within this range, the elasticity, flexibility and adhesionof the undercoat layer can be excellent.

(3) Photoinitiator: the photoinitiator may be included to form a clearlayer by photocuring the undercoating agent. In one embodiment, thephotoinitiator may include one or more of2-hydroxy-2-methyl-1-phenylpropane-1-phenone,1-hydroxycyclohexylphenylketone, benzophenone, 1-(4-isopropylphenyl)2-hydroxy 2-methyl 1-one,1-[4-(2-hydroxyethoxy)phenyl]-2-hydroxy-2-methyl propane-1-one, α,α-diethoxyacetophenone, 2,2-diethoxy 1-phenylethanone andbis(2,4,6-trimethyl benzoyl)-phenylphosphine oxide.

In one embodiment, the photoinitiator is present in an amount of 0.5 to5% by weight based on the total weight of the undercoating agent. Whenthe photoinitiator is present in an amount within this range,deterioration in the mechanical properties of the undercoat layer can beprevented, and reactivity and workability can be excellent.

(4) Third solvent: the third solvent makes it easy to adjust theviscosity of the undercoating agent and improves the smoothness of theundercoat layer and workability during coating.

In one embodiment, the third solvent may include at least one of theaforementioned fast-drying solvent and a slow-drying solvent.

In one embodiment, the fast-drying solvent may be a solvent having anevaporation rate measured according to ASTM D 3539, higher than 0.8. Inone embodiment, the fast-drying solvent may include: a hydrocarbon-basedsolvent such as n-hexane, n-octane, isooctane or cyclohexane; anaromatic hydrocarbon solvent such as toluene, xylene or mesitylene; analcohol solvent such as methanol, ethanol, n-propyl alcohol or isopropylalcohol; an ether solvent such as diethyl ether, dipropyl ether, dibutylether, tetrahydrofuran, dioxane or cyclopentylmethyl ether; an estersolvent such as ethyl acetate, n-propylacetate, isopropyl acetate, orn-butyl acetate; a ketone solvent such as acetone, methyl ethyl ketone,methyl-n-butyl ketone, or methyl isobutyl ketone; or the like.

In one embodiment, the third solvent may include a fast-drying solventhaving a high drying rate and a slow-drying solvent having a relativelylow drying rate. The slow-drying solvent may be a solvent having anevaporation rate, measured according to ASTM D 3539, of 0.8 or less. Inone embodiment, the slow-drying solvent may include: a hydrocarbonsolvent such as dodecane or undecane; an aromatic hydrocarbon solventsuch as xylene or mesitylene; an alcohol solvent such as n-butanol,hexanol, 3-methyl-3-methoxybutanol, 3-methoxybutanol, methylcellosolve,ethylcellosolve, butylcellosolve, methylcarbitol, ethylcarbitol,butylcarbitol, propylene glycol monomethyl ether, propylene glycolmonoethyl ether, propylene glycol monopropyl ether, propylene glycolmono-n-butyl ether, propylene glycol mono-t-butyl ether, ethylene glycolmono-t-butyl ether, dipropylene glycol monomethyl ether, dipropyleneglycol monoethyl ether, dipropylene glycol monopropyl ether, dipropyleneglycol monobutyl ether and diacetone alcohol; an ether solvent such asdiethylene glycol methyl ethyl ether, diethylene glycol dimethyl ether,diethylene glycol diethyl ether, dipropylene glycol dimethyl ether,diethylene glycol dibutyl ether, propylene glycol monomethyl etheracetate, propylene glycol monoethyl ether acetate, propylene glycolmonopropyl ether acetate and dipropylene glycol monomethyl etheracetate; an ester solvent; a ketone solvent such as diisobutyl ketone,ethyl amyl ketone, 2-heptanone, 2-hexanone, 2-octanone, cyclopentanoneand cyclohexanone; an amide solvent such as N,N-dimethylformamide andN,N-dimethylacetamide; or a lactone solvent such as γ-butyrolactone.

In one embodiment, the third solvent may include the fast-drying solventand the slow-drying solvent in a weight ratio of 1:0.3 to 1:1.5. Whenthe fast-drying solvent and the slow-drying solvent are present withinthe above weight ratio range, the ingredients of the undercoating agentcan be easily dispersed, and photocuring efficiency can be excellent.

In one embodiment, the third solvent may be present in an amount of 30to 75% by weight based on the total weight of the undercoating agent.Within this range, deterioration in the smoothness and the appearance ofthe undercoating layer can be prevented and miscibility, dispersibilityand workability may be excellent.

(5) Additives: In one embodiment, the undercoating agent may furtherinclude additives. These components may be included to improve theworkability, light resistance and smoothness of the undercoating agent.The additive may include one or more of a leveling agent, a lightstabilizer, an antifoaming agent and a wetting agent, but is not limitedthereto. In one embodiment, the additive may be present in an amount of0.01 to 10% by weight based on the total weight of the undercoatingagent. For example, the leveling agent may include a silicon-basedleveling agent.

In one embodiment, the thickness of the undercoat layer may be 3 to 100μm. Within this thickness range, the adhesion and mechanical propertiesof the undercoat layer can be excellent.

The color coating layer imparts color to a multiple coating layeraccording to the present disclosure, and can be combined with the metaltexture representation of the plating layer to provide excellentaesthetics. Hereinafter, the ingredients of the color coating agent willbe described in more detail.

Color Coating Agent

The color coating agent contains 10 to 35% by weight of a modifiedacrylic resin, 1 to 25% by weight of a pigment and 40 to 80% by weightof a first solvent.

(1) Modified acrylic resin: In one embodiment, the modified acrylicresin may have a weight average molecular weight of 5,000 to 50,000g/mol. Under the above conditions, it is easy to adjust the viscosity,and thus workability when forming the color coating layer, the hardnessof the coating film, adhesion and scratch resistance can be excellent.

In one embodiment, the modified acrylic resin is present in an amount of10 to 35% by weight based on the total weight of the color coatingagent. When the modified acrylic resin is present in less than 10% byweight, the durability of the color coating layer is lowered, and whenthe modified acrylic resin is present in an amount exceeding 35% byweight, miscibility, workability and dispersibility may be deteriorated.

(2) Pigment: The pigment is included to impart color to the colorcoating layer. In one embodiment, the pigment may include componentsknown in the art without limitation. For example, the pigment mayinclude a known pigment such as pigment red, pigment green, pigmentblue, pigment yellow, pigment violet or the like. Other examples thereofinclude known pigments such as silica, carbon black, iron oxide,titanium oxide (TiO₂), antimony (Sb), quinacridone,copper-phthalocyanine and chromium (Cr).

In one embodiment, the pigment is present in an amount of 1 to 25% byweight based on the total weight of the color coating agent. When thepigment is present in an amount less than 1% by weight, aesthetics aredeteriorated due to the insignificant coloring effect, and when thepigment is present in an amount exceeding 25% by weight, thedispersibility and miscibility of the color coating agent and theinterlayer adhesion and mechanical properties of the color coating layermay be deteriorated.

(3) First solvent: The first solvent makes it easy to adjust theviscosity of the color coating agent and improves the smoothness of thecoating layer and workability during coating.

In one embodiment, the first solvent may include a fast-drying solventand a slow-drying solvent in a weight ratio of 1:1 to 1:3. When thefast-drying solvent and the slow-drying solvent are present within theabove weight ratio range, the ingredients of the color coating agent canbe easily dispersed, and drying efficiency during thermal drying and theappearance of the prepared color coating layer, such as smoothnessthereof, can be excellent. Since the fast-drying solvent and theslow-drying solvent use the same ingredients as described above, adetailed description thereof will be omitted.

In one embodiment, the first solvent is present in an amount of 40 to80% by weight based on the total weight of the color coating agent. Whenthe first solvent is present in an amount of less than 40% by weight,dispersibility and miscibility are deteriorated, and when the firstsolvent is present in an amount exceeding 80% by weight, the drying timeincreases, resulting in poor workability, surface defects in the colorcoating layer, or deterioration in physical properties.

(5) Additives: In one embodiment, the color coating agent may furtherinclude so additives. These components may be included to improve theworkability, light resistance and smoothness of the color coating agent.The additive may include one or more of a leveling agent, a lightstabilizer, an antifoaming agent and a wetting agent, but is not limitedthereto. In one embodiment, the additive may be present in an amount of0.01 to 10% by weight based on the total weight of the color coatingagent. For example, the leveling agent may include a silicon-basedleveling agent.

In one embodiment, the color coating layer may be formed by drying theapplied color coating agent at 60 to 80° C. Under these conditions, thedurability of the color coating agent can be excellent.

In one embodiment, the thickness of the color coating agent may be 1 to100 μm. Within this thickness range, the adhesion and mechanicalproperties of the color coating layer can be excellent. For example, thethickness may be 15 to 100 μm.

(S20) Forming Clear Layer

In this step, a clear coating agent is applied on the surface of thecolor coating layer, and is then dried to form a clear layer. In oneembodiment, the clear coating agent may be applied and photocured toform a clear layer. The clear coating agent includes 10 to 30% by weightof a polyester-modified acrylic resin, 5 to 25% by weight of an acrylicoligomer, 5 to 45% by weight of an acrylic monomer, 1 to 15% by weightof a photoinitiator, and 10 to 75% by weight of a second solvent.Hereinafter, the components of the clear coating agent will be describedin more detail.

Clear Coating Agent

(1) Polyester-modified acrylic resin: the polyester-modified acrylicresin may be included in order to improve the scratch resistance,chipping resistance, flexibility and interlayer adhesion of the clearlayer.

In one embodiment, the polyester-modified acrylic resin may be preparedby polymerizing an unsaturated polybasic acid with a first reactionproduct, prepared through condensation between a polyhydric alcohol anda polybasic acid, to prepare a polyester precursor having a double bondat the end thereof and then polymerizing the polyester precursor with anacrylic monomer.

In one embodiment, the polyester-modified acrylic resin may have aweight average molecular weight of 5,000 to 50,000 g/mol, a hydroxylvalue of 30 to 250 mgKOH/g, and a glass transition temperature of 40 to90° C. Under the above conditions, the viscosity can be easily adjustedand thus workability can be excellent, and chipping resistance,hardness, adhesion and scratch resistance of the clear layer can besuperior.

In one embodiment, the polyester-modified acrylic resin may be presentin an amount of 10 to 30% by weight based on the total weight of theclear coating agent. When the polyester-modified acrylic resin ispresent in an amount of less than 10% by weight, the chippingresistance, hardness, flexibility and adhesion of the clear layer may bedeteriorated, and when the polyester-modified acrylic resin is presentin an amount exceeding 30% by weight, the miscibility and dispersibilityof the clear coating layer may be deteriorated.

(2) Acrylic oligomer: In one embodiment, the acrylic monomer may includean acrylate oligomer having two or more polymerizable functional groups.The acrylic oligomer may have a weight average molecular weight of 500to 6,000 g/mol. Under the above conditions, the mechanical properties ofthe clear layer can be excellent.

In one embodiment, the acrylic oligomer is present in an amount of 5 to25% by weight based on the total weight of the clear coating agent. Whenthe acrylic oligomer is present in an amount less than 5% by weight,adhesion and photocuring efficiency may be deteriorated, and when theacrylic oligomer is present in an amount exceeding 25% by weight, themechanical strength of the clear coating layer may be deteriorated.

(3) Acrylic monomer: In one embodiment, the acrylic monomer may includean acrylate monomer having two or more polymerizable functional groups.

In one embodiment, the acrylic monomer is present in an amount of 5 to45% by weight based on the total weight of the clear coating agent. Whenthe acrylic monomer is present in an amount less than 5% by weight,adhesion and photocuring efficiency may be deteriorated, and when theacrylic monomer is present in an amount exceeding 45% by weight, themechanical strength of the clear coating layer may be deteriorated.

For example, the acrylic monomer and the acrylic oligomer may be presentat a weight ratio of 1:2 to 1:4. Within the weight ratio defined above,miscibility, photocuring efficiency and workability can be excellent.

(4) Photoinitiator: the photoinitiator may be included to form a clearlayer by photocuring the clear coating agent. In one embodiment, thephotoinitiator may include one or more of2-hydroxy-2-methyl-1-phenylpropane-1-phenone,1-hydroxycyclohexylphenylketone, benzophenone, 1-(4-isopropylphenyl)2-hydroxy 2-methyl 1-one,1-[4-(2-hydroxyethoxy)phenyl]-2-hydroxy-2-methyl propane-1-one, α,α-diethoxyacetophenone, 2,2-diethoxy 1-phenylethanone andbis(2,4,6-trimethyl benzoyl)-phenylphosphine oxide.

In one embodiment, the photoinitiator is present in an amount of 1 to15% by weight based on the total weight of the clear coating agent. Whenthe photoinitiator is present in an amount of less than 1% by weight,photocuring does not proceed easily, and when the photoinitiator ispresent in an amount exceeding 15% by weight, the workability andmechanical properties of the clear coating layer may be deteriorated.

(5) Second solvent: The second solvent makes it easy to adjust theviscosity of the clear coating agent and improves the smoothness of theclear layer and workability during photocuring.

In one embodiment, the second solvent may include a fast-drying solventand a slow-drying solvent at a weight ratio of 1:0.8 to 1:2. When thefast-drying solvent and the slow-drying solvent are present within theabove weight ratio range, the ingredients of the clear coating agent canbe easily dispersed, and drying efficiency during photocuring and theappearance of the prepared clear coating layer, such as the smoothnessthereof, can be excellent. Since the fast-drying solvent and theslow-drying solvent use the same ingredients as described above, adetailed description thereof will be omitted.

In one embodiment, the second solvent is present in an amount of 10 to75% by weight based on the total weight of the clear coating agent. Whenthe second solvent is present in an amount of less than 10% by weight,dispersibility and miscibility are deteriorated, and when the secondsolvent is present in an amount exceeding 75% by weight, the drying timeincreases, resulting in poor workability, surface defects in the clearcoating layer, or deterioration in physical properties.

In one embodiment, the clear coating agent may include at least one of0.1 to 5% by weight of a light stabilizer, 0.1 to 5% by weight of a heatstabilizer, 0.1 to 5% by weight of an adhesion promoter, and 0.1 to 10%by weight of an additive based on the total weight of the clear coatingagent.

(6) Light stabilizer: The light stabilizer may be included to preventsurface defects in the clear layer and improve light stability andweather resistance. For example, the light stabilizer may include one ormore of a triazine ultraviolet light stabilizer and a hindered aminelight stabilizer (HALS).

In one embodiment, the triazine UV absorber includes 6-bis(2,4-dimethylphenyl)]-1,3,5-triazine, 6-bis(2,4-dimethylphenyl)-1,3,5triazine and tris2,4,6-[2-4-(octyl-2-methylethanoate)oxy-2-hydroxyphenyl]-1,3,5 triazineor the like. These may be used alone or in combinations of two or more,but the present disclosure is not limited thereto.

In one embodiment, the hindered amine UV stabilizer may be2,2,6,6-tetramethyl-4-piperidyl stearate,1,2,2,6,6-pentamethyl-4-piperidyl benzoate,N-(2,2,6,6-tetramethyl-4-piperidyl) dodecylsuccinimide,1-[(3,5-di-t-butyl-4-hydroxyphenyl)propionyloxyethyl]-2,2,6,6-tetramethyl-4-piperidyl-(3,5-di-t-butyl-4-hydroxyphenyl)propionate,bis(2,2,6,6-tetramethyl-4-piperidyl) sebacate,bis(1,2,2,6,6-pentamethyl-4-piperidyl)sebacate,bis(1,2,2,6,6-pentamethyl-4-piperidyl)-2-butyl-2-(3,5-di-t-butyl-4-hydroxybenzyl)malonate,N, N′-bis(2,2,6,6-tetramethyl-4-piperidyl)hexamethylenediamine, tetra(2,2,6,6-tetramethyl-4-piperidyl) butanetetracarboxylate, tetra(1,2,2,6,6-pentamethyl-4-piperidyl) butanetetracarboxylate and bis(2,2,6,6-tetramethyl-4-piperidyl)-di(tridecyl)butanetetracarboxylate orthe like. These may be used alone or in combinations of two or more, butthe present disclosure is not limited thereto.

The light stabilizer may be present in an amount of 0.1 to 5% by weightbased on the total weight of the clear coating agent. When the lightstabilizer is present in an amount within the above range, surfacedefects of the clear layer can be prevented, and weather resistance andan anti-yellowing effect can be excellent.

(7) Heat stabilizer: The heat stabilizer may include a phenol-based,phosphite-based or lactone-based heat stabilizer or the like. In oneembodiment, the heat stabilizer may be present in an amount of 0.1 to 5%by weight based on the total weight of the clear coating agent. When theheat stabilizer is present in an amount within this range, thermalstability can be excellent and deterioration in mechanical properties ofthe clear layer can be prevented.

(8) Adhesion promoter: The adhesion promoter may include an etheradhesion promoter. In one embodiment, the adhesion promoter may bepresent in an amount of 0.1 to 5% by weight based on the total weight ofthe clear coating agent. When the adhesion promoter is present in anamount within the above range, interlayer adhesion can be excellent, anddeterioration in mechanical properties of the clear layer can beprevented.

(9) Additive: The additive may include, but is not limited to, one ormore of a leveling agent, an antifoaming agent and a wetting agent. Inone embodiment, the additive may be present in an amount of 0.01 to 10%by weight based on the total weight of the clear coating agent. Forexample, the leveling agent may include a silicon-based leveling agent.

In one embodiment, the thickness of the clear layer may be 10 to 50 μm.Within the thickness range, the adhesion of the clear layer can beexcellent, and mechanical properties such as weather resistance andchipping resistance can be excellent. For example, the thickness of theclear layer may be 20 to 30 μm.

In one embodiment, the sum of the thickness of the color coating layerand the clear layer may be 15 to 90 μm. Under the above condition, theappearance can be excellent, and mechanical properties such as weatherresistance and chipping resistance can be excellent. For example, thesum of the thickness may be 45 to 85 μm.

In one embodiment, the color coating layer and the clear layer may beformed at a thickness ratio of 1:1.2 to 1:3. Within this thickness ratiorange, both appearance and chipping resistance can be excellent.

In addition, there is no particular limitation as to the method ofapplying the undercoating agent, color coating agent and clear coatingagent. For example, brushing, spray coating, dip coating, spin coatingand the like, all of which are widely used in the art, may be used, butthe present disclosure is not limited thereto.

Molded Article Manufactured Using Method of Forming Multiple Coating onPlating Member

Another aspect of the present disclosure relates to a molded articlemanufactured using the method of forming the multiple coating on theplating member. FIG. 2 shows a molded article according to oneembodiment of the present disclosure. Referring to FIG. 2, the moldedarticle 1000 includes a substrate 110, an undercoat layer 120 formed ona surface of at least a part of the substrate 110, a plating layer 130formed on a surface of the undercoat layer 120, a color coating layer200 formed on the surface of the plating layer 130, and a clear layer300 formed on the surface of the color coating layer 200.

The color coating layer is formed using a color coating agent containing10 to 35% by weight of a modified acrylic resin, 1 to 25% by weight of apigment and 40 to 80% by weight of a first solvent, wherein the clearcoating layer is formed using a clear coating agent containing 10 to 30%by weight of a polyester-modified acrylic resin, 5 to 25% by weight ofan acrylic oligomer, 5 to 45% by weight of an acrylic monomer, 1 to 15%by weight of a photoinitiator and 10 to 75% by weight of a secondsolvent.

The plating member includes a substrate, an undercoat layer formed onthe surface of at least a portion of the substrate, and a plating layerformed on the surface of the undercoat layer.

In one embodiment, the undercoat layer may be formed by applying anundercoating agent containing 10 to 65% by weight of an acryliccompound, 0.1 to 5% by weight of a polyester-modified acrylic resin, 0.5to 5% by weight of a photoinitiator and 30 to 75% by weight of a thirdsolvent onto at least one surface of the substrate, followed by curing.Since the ingredients and the contents constituting the undercoatingagent, the color coating agent and the clear coating agent are the sameas described above, a detailed description thereof will be omitted.

In one embodiment, the thickness of the undercoat layer may be 10 to 50μm. In the thickness range, the adhesion and mechanical properties ofthe undercoat layer can be excellent.

In one embodiment, the thickness of the plating layer may be 1 to 50 μm.Within the thickness range, the adhesion and appearance of the platinglayer can be excellent.

In one embodiment, the thickness of the color coating layer may be 10 to30 μm. Within the thickness range, chipping resistance, adhesion andappearance of the color coating layer can be excellent. For example, thethickness may be 15 to 20 μm.

In one embodiment, the thickness of the clear layer may be 10 to 50 μm.Within the thickness range, the adhesion of the clear layer can beexcellent, and mechanical properties such as weather resistance andchipping resistance can be excellent. For example, the thickness may be20 to 30 μm.

In one embodiment, the sum of the thickness of the color coating layerand the clear layer may be 15 to 90 μm. Under the above conditions,appearance as well as mechanical properties such as weather resistanceand chipping resistance can be excellent. For example, the sum of thethickness may be 45 to 85 μm.

In one embodiment, the color coating layer and the clear layer may beformed in a thickness ratio of 1:1.2 to 1:3. Within the thickness ratiorange, both appearance and chipping resistance can be excellent.

In one embodiment, the molded article may be a vehicle radiator grille,but the present disclosure is not limited thereto.

Hereinafter, the configurations and operations of the present disclosurewill be described in more detail with reference to preferred embodimentsof the present disclosure. However, these embodiments are provided aspreferred examples of the present disclosure, and should not beconstrued as limiting the present disclosure by any means. Details thatare not described herein can be sufficiently and technically conceivedby those skilled in the art and thus will be omitted.

EXAMPLES AND COMPARATIVE EXAMPLES Example 1

(1) Preparation of plating member: an undercoating agent containing 10to 65% by weight of an acrylic compound (including an acrylic monomerand an acrylic oligomer), 0.1 to 5% by weight of a polyester-modifiedacrylic resin, 0.5 to 5% by weight of a photoinitiator and 30 to 75% byweight of a third solvent was applied onto the surface of a substrate(ABS material) and was then photocured by irradiation with ultravioletrays at a dose of 800 to 2,000 mJ/cm² to form an undercoat layer havinga thickness of 5 to 25 μm. Then, chromium (Cr) was vacuum-deposited onthe surface of the undercoat layer to form a plating layer having athickness of 5 to 30 μm.

(2) Formation of color coating layer: a color coating agent containing10 to 35% by weight of a modified acrylic resin, 1 to 25% by weight of apigment (including a violet pigment and a red pigment), 40 to 80% byweight of a first solvent and 0.1 to 5% by weight of an additive(leveling agent) was prepared.

The color coating agent was applied onto the surface of the platinglayer and was then thermally dried at 60 to 80° C. to prepare a colorcoating layer having a thickness of 30.3 μm.

(3) Formation of clear layer: a clear layer agent containing 10 to 30%by weight of a polyester-modified acrylic resin, 5 to 25% by weight ofan acrylic oligomer, 5 to 45% by weight of an acrylic monomer, 1 to 15%by weight of a photoinitiator, 10 to 75% by weight of a second solvent,0.1 to 5% by weight of a light stabilizer, 0.1 to 5% by weight of a heatstabilizer, 0.1 to 5% by weight of an adhesion promoter and 0.1 to 10%by weight of an additive (leveling agent) was prepared.

The clear coating agent was applied onto the surface of the colorcoating layer, and was then photocured by irradiation with ultravioletlight at a dose of 800 to 2,000 mJ/cm² to form a clear layer having athickness of 51.3 μm and thereby to prepare a molded article specimen asshown in FIG. 3.

Example 2

(1) Preparation of plating member: an undercoating agent containing 10to 65% by weight of an acrylic compound (including an acrylic monomerand an acrylic oligomer), 0.1 to 5% by weight of a polyester-modifiedacrylic resin, 0.5 to 5% by weight of a photoinitiator and 30 to 75% byweight of a third solvent was applied onto the surface of a substrate(ABS material) and was then photocured by irradiation with ultravioletrays at a dose of 800 to 2,000 mJ/cm² to form an undercoat layer havinga thickness of 5 to 25 μm. Then, stainless steel (SUS) wasvacuum-deposited on the surface of the undercoat layer to form a platinglayer having a thickness of 5 to 30 μm.

In addition, a color coating layer having a thickness of 17.1 μm and aclear layer having a thickness of 38.1 μm were formed in the same manneras in Example 1 except that 1 to 25% by weight of a pigment including ablack pigment and a blue pigment was applied as a pigment of the colorcoating agent to form a molded article specimen as shown in FIG. 3.

Physical Property Evaluation Test

The physical properties of specimens of Examples 1 to 2 were evaluatedbased on the Hyundai-Kia Motors MS625-01 standard as shown in Table 1below, and the results are shown in Table 2 below.

TABLE 1 Test item Test method and standard (MS625-01) Pencil hardness HBor higher Adhesive force M-1~M-2.5 Impact Coating film has fine cracks,but should not be resistance detached. (4-score evaluation-Very good: ●,good: ◯, moderate: ▴, bad: X) Water Coating films should have nodiscoloration, bleaching, resistance swelling, cracks and glossdeterioration and the like Saline and adhesive force of M-1 to M-2.5.resistance (4-score evaluation-Very good: ◯, moderate: ▴, Acidresistance bad: X) Alkali resistance Chemical resistance Heat resistanceCoating films should have no swelling, cracks, gloss cycle deteriorationor the like, and have adhesive force of M-1 to M-2.5. High-pressureAfter the test, coating films should have a detachment car cleaning sizeof less than 2 mm (one scale) and have no (MS655-14) problems such asswelling or cracks. (4-score evaluation-Very good: ●, good: ◯, moderate:▴, bad: X) Weather Coating films should have no discoloration,bleaching, resistance swelling, cracks, gloss deterioration or the likeand have adhesive force of M-1 to M-2.5. (4-score evaluation-Very good:●, good: ◯, moderate: ▴, bad: X) Chipping After tests of threespecimens, two or more specimens resistance should satisfy the followingconditions: scratches (MS655-14) having a chipping size of 1 mm or moreshould be 3 or less. In this case, scratches having a chipping size ofless than 1 mm or scratches wherein an adherent is not exposed will beexcluded from evaluation (4-score evaluation-Very good: ●, good: ◯,moderate: ▴, bad: X)

TABLE 2 Test item Example 1 Example 2 Pencil hardness ● ● Adhesive force● ● Impact resistance ● ● Water resistance OK (M 2.5) OK (M 2.5) Salineresistance OK (M 2.5) OK (M 2.5) Acid resistance ● ● Alkali resistance ●● Oil resistance ● ● Chemical resistance ● ● Fuel oil resistance ● ● Waxresistance ● ● Gasoline resistance ● ● Heat resistance cycle OK (M 2.3)OK (M 2.3) High-pressure car cleaning ● ● Weather resistance ● ●Chipping resistance ● ●

As can be seen from the results of Table 2, the molded articles ofExamples 1 to 2 according to the present disclosure have excellentappearance, chipping resistance, scratching resistance, durability,chemical resistance and weather resistance and are lightweight, and thuscan efficiently replace conventional metal parts, and have excellentlight resistance and adhesive force between the coating layer and thecoating layer.

As apparent from the foregoing, the method of forming the multiplecoating on the dry plating member according to the present disclosureand the molded article manufactured thereby are highly lightweight andexhibit excellent chipping resistance, scratch resistance, durability,appearance, chemical resistance, weather resistance, light resistanceand adhesive force between the substrate, the plating layer and thecoating layer.

The effects of the present disclosure are not limited to those mentionedabove. It should be understood that the effects of the presentdisclosure include all effects that can be inferred from the foregoingdescription of the present disclosure.

The present disclosure has been described in detail with reference topreferred embodiments thereof. However, it will be appreciated by thoseskilled in the art that changes may be made in these embodiments withoutdeparting from the principles and spirit of the present disclosure, thescope of which is defined in the appended so claims and theirequivalents.

1. A molded article comprising: a substrate; an undercoat layer formedon a surface of at least a part of the substrate; a plating layer formedon a surface of the undercoat layer; a color coating layer formed on asurface of the plating layer; and a clear layer formed on a surface ofthe color coating layer, wherein the color coating layer is formed usinga color coating agent comprising 10 to 35% by weight of a modifiedacrylic resin, 1 to 25% by weight of a pigment and 40 to 80% by weightof a first solvent based on a total weight of the color coating agent,and wherein the clear layer is formed using a clear coating agentcomprising 10 to 30% by weight of a polyester-modified acrylic resin, 5to 25% by weight of an acrylic oligomer, 5 to 45% by weight of anacrylic monomer, 1 to 15% by weight of a photoinitiator and 10 to 75% byweight of a second solvent based on a total weight of the clear coatingagent.